Rhythm and rate disturbances preceding sustained ventricular arrhythmia in patients with secondary implanted cardioverter defibrillators

Abstract

Ventricular arrhythmia is one of the most common causes of cardiac arrest. One of the treatment measures in patients with heart disease with ventricular arrhythmia is the implantation of implantable cardioverter defibrillators (ICD) to prevent sudden death. Knowing the state of the heart beats before the arrhythmia can be a guide to carry out the appropriate treatment to prevent or treat recurrent arrhythmias. This study was designed and implemented to investigate the regularity and number of disturbances before persistent ventricular arrhythmias in patients undergoing secondary implantation of implantable cardiac shock devices. Methods: In this -cross-sectional study, 150 patients who underwent secondary ICD implantation for any reason from April 1, 2023 to April 1, 2024 and had at least one ventricular arrhythmia event in the ICD memory after implantation were included. The exclusion criteria were patient's unwillingness to participate in the research, lack of access to demographic findings during the patient's hospitalization, incomplete data in the patients' clinical records, and age below 18 years. The results of the study were reported using descriptive statistics methods. The significance level in this study is P-value<0.05 and statistical analysis was done by SPSS 25 software. Results: The average age of the patients in this study was 58.24 years. 84 of these patients were implanted with an ICD-DR device. The average heart rate of the patients was 73.33. The overall average QRS wavelength in the patients of this study was 122.53. 1 The most episodes occurred in the patients of this study at 01:00. 128 patients had ventricular tachycardia (VT) during the episode, the average rate was 197.71. The highest number of VT and ventricular fibrillation (VF) occurred in patients who underwent ICD-DR implantation. In general, the heart rate of the patients was 73.33. The ratio of ventricular and atrial extrasystoles to the total number of heartbeats of the patient before the occurrence of arrhythmia was 68% and 8%, respectively. Also, the frequency of atrial fibrillation in these patients was 8%.